Binoculars have been in use for a very long time. Even high-powered prism binoculars, magnifying from six to ten times, have been in use for over 140 years, ever since the Italian, Porro, invented the right angle prism, a pair of which could mirror the upside-down image of the objective the 4 times required to turn it right-side-up and correct it right to left. But such binoculars were for distance viewing only and a modern prism binocular customarily has a focus range from about ten feet to infinity.